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Study Information
Study Attribute Value
CEBS Accession Number: 002-02088-0009-0000-9
Chemical Name: Diphenhydramine hydrochloride
CASRN: 147-24-0
NTP Study Type: Genetic Toxicology - Mammalian Cell Mutagenicity
NTP Study ID: 590709
Study Result: Negative


Table Instructions and Notes:
Studies are indicated to be "Nontoxic" when the observed reductions in relative total growth did not indicate that the maximum tolerated dose was achieved.

Nonactivation Trial: 1 Experiment Call: Equivocal
  Conc.
ug/mL
Cloning
Efficiency
Relative Total
Growth
Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water
 0         
104 91 94 30 30
    110 98 105 32
    102 103 89 29
    91 108 75 27
Test Chemical Diphenhydramine hydrochloride
20         
100 72 103 35 35
    88 77 89 34
    91 70 96 35
 
30         
96 54 92 32 30
    92 51 79 29
    90 71 82 30
 
40         
88 49 71 27 32
    101 54 98 33
    91 51 96 35
 
50         
100 34 117 39 33
    89 41 90 34
    94# 50 72 26
 
60         
99 40 95 32 35
    74 37 70 32
    87# 32 108 42
 
80         
58 9 105 61 59*
    71 9 129 60
    78 10 131 56
Positive Control Methyl Methane Sulfonate
5         
94 52 477 169 168*
    67 32 351 174
    85 48 407 159

Nonactivation Trial: 2 Experiment Call: Negative
  Conc.
ug/mL
Cloning
Efficiency
Relative Total
Growth
Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water
 0         
109 118 127 39 39
    103 94 114 37
    110 83 127 38
    110 105 142 43
Test Chemical Diphenhydramine hydrochloride
20         
91 49 78 29 29
    78 49 61 26
    72 50 69 32
 
30         
104 64 86 28 32
    83 59 90 36
    107 43 105 33
 
40         
94 53 55 19 23
    109 43 71 22
    102 53 83 27
 
50         
156r 49 136 29 33
    101 32 118 39
    95 41 76 27
 
60         
109 37 122 37
    123r 23 99 27
    121r 40 113 31
 
80         
104 12 72 23 25
    102 9 108 35
    110 15 55 17
 
100         
   
   
Positive Control Methyl Methane Sulfonate
5         
56# 32 447 265 328*
    42 21 550 442
    69 30 574 278

Nonactivation Trial: 3 Experiment Call: Negative
  Conc.
ug/mL
Cloning
Efficiency
Relative Total
Growth
Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water
 0         
102 88 93 30 29
    116 103 91 26
    107 81 111 35
    112 128 88 26
Test Chemical Diphenhydramine hydrochloride
40         
120 64 59 16 21
    113 45 93 28
    109 60 63 19
 
50         
113# 40 64 19 20
    94 41 58 21
    96 38 61 21
 
60         
110 41 57 17 20
    99 38 63 21
    116 40 76 22
 
70         
97 19 77 27 25
    104 19 82 26
    87 19 56 22
 
80         
114 19 57 17 17
   
    108 23 55 17
 
100         
105 7 76 24 21
   
    111 6 61 18
 
120         
   
   
Positive Control Methyl Methane Sulfonate
5         
55 21 408 248 219*
    89 37 454 171
    66 31 473 239

Induced S9 Trial: 1 Experiment Call: Inconclusive
  Conc.
ug/mL
Cloning
Efficiency
Relative Total
Growth
Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water
 0         
86 87 125 48 34
    91 96 85 31
    96 120 81 28
    95 97 85 30
Test Chemical Diphenhydramine hydrochloride
10         
94 123 85 30 28
    119 160 79 22
    94 105 88 31
 
20         
102 117 158 51 48
    82 103 104 42
    77# 96 119 51
 
30         
87 103 82 32 33
    94 101 88 31
    98 99 104 35
 
40         
88 108 61 23 28
    91 107 92 34
    86 100 72 28
 
60         
97 91 101 35 32
    105 92 105 33
    93 94 75 27
 
80         
99 105 72 24 32
    92# 88 88 32
    107# 83 130 41
Positive Control 3-Methylcholanthrene
2.5       
74 43 839 380 384*
    86 46 848 330
    62 42 824 443

Induced S9 Trial: 2 Experiment Call: Negative
  Conc.
ug/mL
Cloning
Efficiency
Relative Total
Growth
Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water
 0         
107 110 91 28 33
    105 107 119 38
    117 58 139 39
    120 124 99 28
Test Chemical Diphenhydramine hydrochloride
25         
109 86 151 46 41
    117 104 133 38
    117 87 133 38
 
50         
122r 75 101 28 32
    117 73 96 27
    100 78 111 37
 
75         
136r 56 95 23
    131r 58 71 18
    119 45 110 31
 
100         
124r 30 115 31 23
    90 14 57 21
    114 42 86 25
 
150         
   
   
Positive Control 3-Methylcholanthrene
2.5       
117 68 986 281 308*
    102# 61 982 320
    98 50 948 324

Induced S9 Trial: 3 Experiment Call: Negative
  Conc.
ug/mL
Cloning
Efficiency
Relative Total
Growth
Mutant Colonies Mutant Frequency Avg Mutant Frequency
Vehicle Control Water
 0         
90 107 102 38 38
    100# 126 84 28
    98 100 73 25
    57 66 105 62
Test Chemical Diphenhydramine hydrochloride
30         
112 104 127 38 37
    106 97 128 40
    93 103 96 35
 
40         
111 102 104 31 39
    86 58 114 44
    84 100 102 41
 
60         
123r 77 139 38 32
    101 69 98 32
    111 82 103 31
 
80         
100 61 112 37 38
    124r 61 136 37
    100 50 114 38
 
100         
105 23 97 31 32
    108 18 122 38
    90 13 77 28
 
120         
   
   
Positive Control 3-Methylcholanthrene
2.5       
96 61 917 320 286*
    95 62 822 288
    97 83 726 249

Footnotes:
Asterisks(*) indicate significant responses.
r = rejected value due to quality control criteria
# = reduced sample size because of the loss of one culture dish due to contamination